Further Reading

The attacks are able to bypass security protections Microsoft engineers have gradually added to later versions of their software. The exploits appear to circumvent the measures, at least in part, by exploiting at least two separate flaws. One flaw allows attackers to access and control computer memory, and another leaks system information needed to capitalize on the first bug.
"The memory access vulnerability is designed to work on Windows XP with IE 7 and 8 and on Windows 7," FireEye researchers Xiaobo Chen and Dan Caselden wrote in a post published Friday. "The exploit targets the English version of Internet Explorer, but we believe the exploit can be easily changed to leverage other languages. Based on our analysis, the vulnerability affects IE 7, 8, 9 and 10."

Early analysis suggests the two vulnerabilities work only against machines running IE 8 on XP and IE 9 running on Windows 7. The research into the attacks is in extremely early stages, so it wouldn't be surprising for the range of vulnerable systems to be wider once more analysis has been done.

An "exceptionally accomplished and elusive" attack

Update: Shortly after Ars published an earlier version of this article on Sunday, FireEye posted a newer analysis of the attack indicating it's part of an unusually sophisticated advanced persistent threat (APT). The attackers embedded the exploit code directly "into a strategically important website, known to draw visitors that are likely interested in national and international security policy," the researchers wrote. The attacks rely on some of the same command and control servers used in a previous APT campaign known as Operation DeputyDog.

Also setting the newly discovered attacks apart from other malware campaigns is the malicious payload that gets installed. Although it's a variant of the previously seen trojan alternately dubbed Hydraq, McRat or Trojan.APT.9002, the new payload runs solely in memory. It doesn't ever write itself to disk, a trait that leaves few to no artifacts for security defenders or forensic investigators to identify infected computers.

"Specifically, the payload is shellcode, which is decoded and directly injected into memory after successful exploitation via a series of steps," the FireEye researchers wrote in the latest post. They went on to write: "By utilizing strategic Web compromises along with in-memory payload delivery tactics and multiple nested methods of obfuscation, this campaign has proven to be exceptionally accomplished and elusive."

As is often the case, the attacks can be blocked by installing the latest version of Microsoft EMET, short for the Enhanced Mitigation Experience Toolkit. Members of Microsoft's security response team have not yet commented on the report, although they are likely to do so soon. Microsoft representatives contacted by Ars said members of the company's security team are still looking in to the report.

FireEye didn't elaborate on the US-based website that was hosting the drive-by exploit, except to describe it as "breached," meaning the attackers were able to take control of it and cause it to attack people who visited it. Based on the description of the exploit and its ability to bypass defenses Microsoft engineers have built into newer versions of IE and Windows, there's reason to believe the attackers put a fair amount of time and skill into their work. Among other things, the attack code exploits a "new information leakage vulnerability and an IE out-of-bounds memory access vulnerability" so it can force computers to execute malicious code.

"The information leak uses a very interesting vulnerability to retrieve the timestamp from the [program executable] headers of msvcrt.dll," the FireEye researchers explained. "The timestamp is sent back to the attacker's server to choose the exploit with a ROP chain specific to that version of msvcrt.dll. This vulnerability affects Windows XP with IE 8 and Windows 7 with IE 9."

ROP is short for "return oriented programming," a technique that repackages benevolent code found in an exploited application in a way that gives it new, malicious capabilities. Attackers use ROP chains to bypass data execution prevention, a security mitigation added to most Microsoft applications in the past seven or so years. It prevents most data loaded into memory from being executed.

With the active circulation of at least two attacks that successfully exploit unpatched or only temporarily patched vulnerabilities in widely used Microsoft software titles, readers would do well to remain on guard. Those who haven't already installed the temporary fix for the earlier-reported TIFF image rendering bug should do so immediately. Users should also upgrade to versions 7 or 8 of Windows and run version 11 of IE. EMET is also a worthwhile mitigation, as is using a browser other than IE whenever possible until more is known about the scope of the attacks.

Promoted Comments

What I don't get is why the people the found the exploit aren't waiting for next year to use it. I mean if they kept quiet and flooded the market after XP went out of extended support I doubt Microsoft security would of bothered to take a 2nd look.

Well it also targets Win7. And of course it depends on the organization you are targeting.

Also, I think a lot of people are already migrating away from XP, I know I will be taking the last XP's machines I have down and moving them to something else.

As is often the case, the attacks can be blocked by installing the latest version of Microsoft EMET, short for the Enhanced Mitigation Exploitation Toolkit. Members of Microsoft's security response team have not yet commented on the report, although they are likely to do so soon. Microsoft representatives contacted by Ars didn't have an immediate comment on the FireEye report.

When is Microsoft finally going to realize they should just ship EMET by default with every version of Windows? It even comes with a list of commonly used applications that would cover the vast majority of software that people use.

I use it on all of my machines and I regularly recommend it to anyone who cares about system security. Inevitably, the first thing they ask me after I tell them about EMET is; "Why doesn't Microsoft just have it installed already with the OS?"

I always have to answer that question with a shrug.

This is almost certainly because EMET can potentially cause problems with third party programs and Microsoft doesn't want to be responsible for supporting another vendor's product.

I do wish they'd bring all the EMET protection mechanisms into supported Windows versions through a service pack so at least things like IE could opt in without requiring EMET.

Is there any real reason to use IE at all, for the average user? My bank rolled out a new version of their site last week that only worked in Chrome (they quickly rolled it back...why didn't they at least test it in IE and FF?). So even bureaucratic behemoths don't seem to consider IE the standard browser any more...

Is there any real reason to use IE at all, for the average user? My bank rolled out a new version of their site last week that only worked in Chrome (they quickly rolled it back...why didn't they at least test it in IE and FF?). So even bureaucratic behemoths don't seem to consider IE the standard browser any more...

I wouldn't use an example of incompetence as support for IE being worthless. Regardless, IE11 is a really good browser and can legitimately make the claim that it is the best browser. Sure, I still prefer Chrome (it's still slightly better for developing in), but I no longer look at people who use it with scorn and derision because it's actually not shit now.

What I don't get is why the people the found the exploit aren't waiting for next year to use it. I mean if they kept quiet and flooded the market after XP went out of extended support I doubt Microsoft security would of bothered to take a 2nd look.

What I don't get is why the people the found the exploit aren't waiting for next year to use it. I mean if they kept quiet and flooded the market after XP went out of extended support I doubt Microsoft security would of bothered to take a 2nd look.

Well it also targets Win7. And of course it depends on the organization you are targeting.

What I don't get is why the people the found the exploit aren't waiting for next year to use it. I mean if they kept quiet and flooded the market after XP went out of extended support I doubt Microsoft security would of bothered to take a 2nd look.

Well it also targets Win7. And of course it depends on the organization you are targeting.

Also, I think a lot of people are already migrating away from XP, I know I will be taking the last XP's machines I have down and moving them to something else.

There's still lots of companies that use it as the de facto browser for their users - as shortsighted as that might be from a security standpoint. Most of the people reading these comments would have FF or Chrome or some other browser for their own use, but a ton of people at those companies will just use what they've been given and that'll be I.E. x.x - and of course their IT departments will have user security update privileges locked down as well.

Hopefully Microsoft can get something out relatively quickly to squash the new browser 0 day.

What I don't get is why the people the found the exploit aren't waiting for next year to use it. I mean if they kept quiet and flooded the market after XP went out of extended support I doubt Microsoft security would of bothered to take a 2nd look.

The attackers have an endless list of zero day exploits. No reason to wait.

You just have to wonder how many 0 days there are? It seems endless. With the arrival of CryptoLocker, I've started hardening my clients' networks greater than ever before. These new 0 days would be an effective transmission vector for CryptoLocker.

I've installed Sandboxie for a number of clients, disabled "hide extensions for known file types" (and explained what to look for when saving attachments, installed Chrome, MalwareBytes in realtime mode (paid version), demote user creds, apply GPOs to disallow EXE launching from the profile, and anything else I can think of.

I use it every day on my Surface 2. It's a far nicer browser than you give it credit. There's even some adblocking and tracking blocking extensions now. I don't know if anyone made the proper comparison or not, but IE11 on the original Surface RT is a noticeably smoother experience than mobile Chrome on the original Nexus 7. Both ran on Tegra 3 hardware and pushed a similar amount of pixels, and IE has full Flash support.

You just have to wonder how many 0 days there are? It seems endless. With the arrival of CryptoLocker, I've started hardening my clients' networks greater than ever before. These new 0 days would be an effective transmission vector for CryptoLocker.

I've installed Sandboxie for a number of clients, disabled "hide extensions for known file types" (and explained what to look for when saving attachments, installed Chrome, MalwareBytes in realtime mode (paid version), demote user creds, apply GPOs to disallow EXE launching from the profile, and anything else I can think of.

Hiding file extensions is the stupidest "feature" ever. Runner up is the icon view of directory contents.

I use it every day on my Surface 2. It's a far nicer browser than you give it credit. There's even some adblocking and tracking blocking extensions now. I don't know if anyone made the proper comparison or not, but IE11 on the original Surface RT is a noticeably smoother experience than mobile Chrome on the original Nexus 7. Both ran on Tegra 3 hardware and pushed a similar amount of pixels, and IE has full Flash support.

I assume he meant on the desktop, but IMO Internet Explorer 11 is by a large margin the best tablet browser available.

As is often the case, the attacks can be blocked by installing the latest version of Microsoft EMET, short for the Enhanced Mitigation Exploitation Toolkit. Members of Microsoft's security response team have not yet commented on the report, although they are likely to do so soon. Microsoft representatives contacted by Ars didn't have an immediate comment on the FireEye report.

When is Microsoft finally going to realize they should just ship EMET by default with every version of Windows? It even comes with a list of commonly used applications that would cover the vast majority of software that people use.

I use it on all of my machines and I regularly recommend it to anyone who cares about system security. Inevitably, the first thing they ask me after I tell them about EMET is; "Why doesn't Microsoft just have it installed already with the OS?"

As is often the case, the attacks can be blocked by installing the latest version of Microsoft EMET, short for the Enhanced Mitigation Exploitation Toolkit. Members of Microsoft's security response team have not yet commented on the report, although they are likely to do so soon. Microsoft representatives contacted by Ars didn't have an immediate comment on the FireEye report.

When is Microsoft finally going to realize they should just ship EMET by default with every version of Windows? It even comes with a list of commonly used applications that would cover the vast majority of software that people use.

I use it on all of my machines and I regularly recommend it to anyone who cares about system security. Inevitably, the first thing they ask me after I tell them about EMET is; "Why doesn't Microsoft just have it installed already with the OS?"

I always have to answer that question with a shrug.

I wonder if that decision was made in anticipation of enterprise customers. Perhaps there was some pushback from some of Microsoft's larger customers due to some incompatibilities with existing software.

That is a reason a number of outfits were still using IE6 long after its practical life--their custom software would have required rewriting to upgrade..

As is often the case, the attacks can be blocked by installing the latest version of Microsoft EMET, short for the Enhanced Mitigation Exploitation Toolkit. Members of Microsoft's security response team have not yet commented on the report, although they are likely to do so soon. Microsoft representatives contacted by Ars didn't have an immediate comment on the FireEye report.

When is Microsoft finally going to realize they should just ship EMET by default with every version of Windows? It even comes with a list of commonly used applications that would cover the vast majority of software that people use.

I use it on all of my machines and I regularly recommend it to anyone who cares about system security. Inevitably, the first thing they ask me after I tell them about EMET is; "Why doesn't Microsoft just have it installed already with the OS?"

I always have to answer that question with a shrug.

This is almost certainly because EMET can potentially cause problems with third party programs and Microsoft doesn't want to be responsible for supporting another vendor's product.

I do wish they'd bring all the EMET protection mechanisms into supported Windows versions through a service pack so at least things like IE could opt in without requiring EMET.

As is often the case, the attacks can be blocked by installing the latest version of Microsoft EMET, short for the Enhanced Mitigation Exploitation Toolkit. Members of Microsoft's security response team have not yet commented on the report, although they are likely to do so soon. Microsoft representatives contacted by Ars didn't have an immediate comment on the FireEye report.

When is Microsoft finally going to realize they should just ship EMET by default with every version of Windows? It even comes with a list of commonly used applications that would cover the vast majority of software that people use.

I use it on all of my machines and I regularly recommend it to anyone who cares about system security. Inevitably, the first thing they ask me after I tell them about EMET is; "Why doesn't Microsoft just have it installed already with the OS?"

I always have to answer that question with a shrug.

This is almost certainly because EMET can potentially cause problems with third party programs and Microsoft doesn't want to be responsible for supporting another vendor's product.

I do wish they'd bring all the EMET protection mechanisms into supported Windows versions through a service pack so at least things like IE could opt in without requiring EMET.

IIRC, all the protections you can add through EMET, are capable of being added through a combination of regedits, Local Group Policy and system settings.

The attackers embedded the exploit code directly "into a strategically important website, known to draw visitors that are likely interested in national and international security policy," the researchers wrote.

Ummm, so why don't they tell us what this infected website is so people don't go visit the site and get infected...?

Is there any real reason to use IE at all, for the average user? My bank rolled out a new version of their site last week that only worked in Chrome (they quickly rolled it back...why didn't they at least test it in IE and FF?). So even bureaucratic behemoths don't seem to consider IE the standard browser any more...

Lots of workplaces still mandate IE.

Also, pity poor Danes, who pretty much have to use IE (with Java, for pity's sake) to reliably do any official/banking related stuff. Their "ebox" system doesn't work properly in other browsers most of the time, so is a complete security nightmare. Not even the WWII spy feel of having an almost one-time pad to carry around as your second auth factor offsets the irritation.

Is there any real reason to use IE at all, for the average user? My bank rolled out a new version of their site last week that only worked in Chrome (they quickly rolled it back...why didn't they at least test it in IE and FF?). So even bureaucratic behemoths don't seem to consider IE the standard browser any more...

Lots of workplaces still mandate IE.

Also, pity poor Danes, who pretty much have to use IE (with Java, for pity's sake) to reliably do any official/banking related stuff. Their "ebox" system doesn't work properly in other browsers most of the time, so is a complete security nightmare. Not even the WWII spy feel of having an almost one-time pad to carry around as your second auth factor offsets the irritation.

Many corporations still use IE since many of their internal sites and portals were built and tested on IE. Regardless, even other traditional browsers such as Chrome and Safari experience similar problems, since the inherent problem lies in the fact that the browser is local to the machine which is browsing the Internet. So if you visit similar sites which have been hacked and implanted with malware, the possibility of becoming infected exists in those browsers as well. This particular instance though definitely has an additional level of complexity to it.It is inevitable that people will visit infected sites. The best solution to this would be to keep the browser totally off the local machine- A virtualized browser, such as Spikes' AirGap is a viable solution to such a problem.